Performance and Variation of White Maize Inbred Lines Developed from Different Sources for Yield and Drought Tolerance

Abstract

Fifty S1, S2 and S3 white maize lines were extracted and developed from five open different populations for searching of new maize inbreds that tolerate drought accompanied with distinct performance as heterotic groups. These lines were evaluated along to ten drought tolerant inbred lines of Maize Section (ARC) under field conditions of normal and stress watering regimes during 2017, 2018 and 2019 seasons, respectively. Anthesis-silking interval (ASI), 100-Kernel weight (K.I), grain yield per plant (GYP) and stress tolerance index (STI) were studied. Watering regimes (W.R) combined across each inbred generation are highly significant source of variation for ASI, KI and GYP. Inbred lines of the three generations varied highly significantly under both watering regimes for K.I, GYP and STI. However, for ASI only all S1's varied significantly under normal irrigation, but S3's are highly significant in both irrigation trials. The S2 and S3 showed somewhat significantly higher reduction for K.I due to drought stress in all groups of inbreds except those of C.1 and ARC. All the groups of inbred lines of the three generations recorded significantly about 8-14% ratios of GYP depression due to drought. The estimates of STI in S1 and S3 over parental origins were higher (1.47 and 1.35) than obtained by S2 (0.88).The developed maize inbreds exhibited desirable performance accompanied with reliable drought tolerance and sufficient variation that offers further responses to upgrading. The validity of obtained inbreds for rolling in maize hybrids programs will be accomplished by assessing the combining abilities as different heterotic groups.